Eccentric bushing



ECCENTRIC BUSHING Filed June 24, 1955 INVENTOR.

ATTOANEY 2,887,905 N v I ECCENTRIC BUSHING 7 Mark H. Frank," Birmingham, Mien, assigiidf to General Motors Corporation, Detroit,'Mich., a corporation of Delaware I L I Application June '24, 1955,Serial No. 517,805 a Claims. or-111 567 This invention relates to eccentric-actuator devicecin general and more particularly to bushing means for use with eccentric actuator devices for minimizing wear occasioned by the use thereof.

Eccentric actuators adapted to effect movement of a control am, such as in engine fuel pump control devices, are subject to appreciable wear upon the eccentric surface thereof. The portion of the control arm engaging the eccentric member is likewise subjected to frictional wear. Since the wearing away of either of the engaging surfaces of these members alters the control aspect intended to be performed and afiects engine durability, the members, or their surfaces, are generally formed of a thicker or more wear resistant material than would otherwise be necessary. Despite such precautions, however, continued operation wears away the members and eventually requires their replacement.

Although other actuator means might be employed in devices where the wearing away of the eccentric and the engaging control arm is of some concern, the eccentric actuator means is an inexpensive and simple control means and its use is generally preferred where cost and simplicity are of importance. Therefore, the means of preventing or minimizing the wear of such members must likewise be both simple in construction and inexpensive, and where such means merely extend the wearing away period, it must also be more simple and less expensive to replace such means than either the eccentric, or the control arm member, or both.

It is here proposed to provide a bushing for use with an eccentric actuator which is free-floating upon the eccentric member and which is retained thereon by the control arm member lightly biased thereagainst. The proposed bushing member comprises a cylindrical sleeve fitting freely upon the eccentric and having an annular flange by means of which the control arm member may retain the bushing upon the eccentric member. The bushing will distribute the engaging force of the control arm more uniformly to the eccentric and being free to float about the eccentric will not itself be subject to localized wear. The bushing is readily removed and replaced, is simple in construction and is of insignificant expense to both the manufacturer and the ultimate user.

In the drawings:

Figure 1 is a cross-sectional fragmentary side view of the end of an engine showing fuel pump control means including the proposed eccentric bushing.

Figure 2 is an end view of a fragmentary part of the engine of Figure 1, having parts broken away and shown in cross-section to illustrate the engine fuel pump means including the proposed eccentric bushing.

An engine having a crankshaft 12 is shown to include a gear member 14 keyed as at 16 to the crankshaft 12 and a gear member 18 keyed as at 20 to the camshaft member 22. A timing chain 24 encircles the gears 14 and 18 and is enclosed within a timing gear cover 26 secured to the end of the engine.

A fuel pump member 28 is secured to the side of the 2,887,900 Pe sPt 9.

engine 10 and includes a control arm 30 extended through an opening 32 formed through the engine wall 34. The control arm member 30 is adapted to actuate the fuel pump in the conventionally'known manne K An eccentric member 36 is secured to the end 'of the camshaft 22 by fastening means 38 extending therethroughand threaded within the camshaft member. The

eccentric is punched as at 40 to extend within a recess 42 formed in the camshaftgear 18 to prevent relative rotation of the eccentric with respect to camshaft rotation; A cylindrical sleeve bushing 44 is disposed upon the eccentric 36 in free-floating relation thereto and includes anannular flange 46 formed at the end thereof adjacent the camshaft gear member18. The fuel pump control arm 30 includes a shoe 48 which bears against'the'eccen tric bushing 44 outwardly of the annular flange 46. The bushing flange 46 restrains axial movement of the bushing member 44 between the camshaft gear 18 and the fuel pump control arm shoe 48 and thereby keeps the bushing on the eccentric without affecting its freedom of rotation relative thereto.

The eccentric bushing 44 is lubricated by means of passage 50, formed through the engine wall 52 between the crankshaft [bearing 54 and the camshaft bearing 56, aperture 58, formed in the camshaft bearing and communicating with passage 50, and passages 60 formed in the camshaft 22 itself. The camshaft thrust plate 62 is also formed to include passages 63 and engine wall 52 is cut back as at 64 to insure the accessibility of lubricant in the vicinity of the eccentric 36, bushing 44 and control arm 30. Lubricant drawn through the aforementioned passages and apertures collects upon the eccentric 36 and its bushing member 44 to lubricate the members and prevent excessive frictional wear due to relative movement therebetween. Excess lubricant falls down into the engine sump shown enclosed by the oil pan 66.

The eccentric bushing 44 may be readily formed by stamping and is easily adapted for use by merely drawing down the fuel pump control arm 30 and slipping the bushing in place over the eccentric member 36. Once the bushing is in place, the fuel pump control arm shoe 48 will keep it located by engagement with the annular flange 46.

The bushing member 44 eliminates the necessity for plating the outer surface of the eccentric 36 with a more wear resistant material and enables the use of a thinner in engine durability.

I claim:

1. Control means including an eccentric member secured to a drive member, a bushing member disposed upon said eccentric and freely disposed for rotation relative thereto, a control arm engaging said bushing member, and an annular flange provided upon said bushing and engaged by said control arm for preventing unintentional removal of said bushing from said eccentric.

2. Control means as provided by claim 1 having said annular flange provided at one end of said bushing member and disposed between said drive member and said control arm.

3. A bushing member in combination with an eccentric member and an eccentric actuated control member, said bushing member being disposed upon said eccentric for free relative rotation with respect to said eccentric and including an annular flange engaged by said eccentric actuated control member to prevent unintentional removal of said bushing member from said eccentric member.

4. Fuel pump control means including an eccentric member secured to a drive member, a sleeve bushing free- 1y disposed upon said eccentric for rotation relative thereto, a fuel pump control arm engaging said bushing, and an annular flange formed from said bushing at one end thereof and disposed between said drive member and said control arm, said control arm retaining said bushing on said eccentric by preventing the passage of said flange from between said drive member and said control arm.

5. Means for preventing excess wear of eccentric actuator means which includes, a bushing member adapted to be disposed upon an eccentric member for free relative rotation with respect thereto, said bushing member being receivable between said eccentric and means actuated thereby, an annular flange formed at one end of said bushing for engagement by said actuated means to prevent unintentional removal of said bushing from said eccentric, and means for providing lubrication between said eccentric and said bushing and between said bushing and said actuated means, said bushing distributing the load of said actuated means more uniformly to said eccentric and preventing localized wear between said members and said actuated means.

References Cited in the file of this patent UNITED STATES PATENTS 505,443 Darragh Sept. 26, 1893 1,108,558 Elmore et a1 Aug. 25, 1914 1,636,499 Chapman et a1 July 19, 1927 1,674,453 Sloper June 19, 1928 2,183,436 Towler et al Dec. 12, 1939 2,611,292 Chandler Sept. 23, 1952 2,654,266 Edelen Oct. 6, 1953 

